Plating apparatus



NOV. 29, 1960 v, DAV|$ 2,962,125

PLATING APPARATUS Filed Feb. 9, 1956 8 Sheets-Sheet 1 A? E .1. I mm Jirr[41 Nov. 29, 1960 J. v. DAVIS PLATING APPARATUS 8 Sheets-Sheet 2 FiledFeb. 9, 1956 J. V. DAVIS PLATING APPARATUS Nov. 29, 1960 Filed Feb. 9,1956 8 Sheets-Sheet 3 IN V EN TQR. Iavzs.

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PLATING APPARATUS Filed Feb. 9, 1956 8 She ets-Sheet 6 1 INVENTOR. JZ$771/, 174/25 Nov. 29, 1960 J. v. DAVIS PLATING APPARATUS 8 Sheets-Sheet 8Filed Feb. 9, 1956 INVENTOR 72717? K jaw 2's.

j I 4rxvr t PLATING APPARATUS John V. Davis, Grosse Pointe, Mich.,assignor to The Udylite Corporation, Detroit, Mich., a corporation ofDelaware Filed Feb. 9, 1956, Ser. No. 564,529

6 Claims. (Cl. 187-1) This invention relates generally to improvedconveyorized machines for electroplating, and more particularly to suchmachines having supporting chassis, or lift frames mounted for verticalmovement on a frame and adapted to convey workpieces through successiveprocessing tanks.

The instant invention comprises improvements in plating machines of thegeneral type described in US. Patent No. 2,479,322 and Re. 24,072. Inthis type of a machine a work-carrying frame structure generally calleda chassis is alternately raised and lowered by means of chains trainedover sprockets and pulled by one or more actuating elements such ashydraulic cylinders or electric motors. It is generally desirable toreduce the weight of the chassis in order to minimize the lifting powerrequirement. The rigidity of the chassis, therefore, is limited by thisconsideration and it has been found desirable to support the chassis atseveral points along its length to insure an even lifting movementthereof and to prevent binding of the chassis on its slide guides. Asthe length of the chassis is increased it becomes increasingly difficultto provide uniform support along its entire length. If a singleactuating element is attached to the various support points by aplurality of chains of dilferent lengths, the stretch characteristics ofthe chains become troublesome. The long chains tend to stretch more thanthe short chains and to permit portions of the chassis remote from theactuating element to sag and as the chassis is raised there is atendency for the chassis to chatter or flutter. If, on the other hand, aplurality of actuating elements is employed it is difficult tosynchronize these elements to insure an even and uniform lifting motionof the chassis.

Accordingly, one object of the instant invention is to improvechassis-type plating machines. Another object is to provide achassis-type plating machine having lifting means which do not requirechains of unequal lengths and which lift the chassis without binding orflutter. Still another object is to provide a chassis-type platingmachine wherein the means for lifting the chassis automaticallyequalizes and coordinates the efforts of a plurality of actuatingelements.

These and other objects are accomplished according to the instantinvention which provides a chassis-type plating machine including achassis lift mechanism comprising a rigid tension bar supported on themachine frame in a horizontal position above and parallel to the chassisfor longitudinal reciprocating travel relative thereto. The tension baris attached to the chassis at a plurality of points by flexible meansand is driven longitudinally in a horizontal direction by actuatingmeans such as a hydraulic cylinder or an electric motor. This horizontalmotion is translated to the chassis through the flexible means to effectuniform lifting and lowering of the chassis. The invention alsocontemplates the useof pairs of such tension bars actuated reciprocallyand linked together through equalizing means so that motion of one inone direction produces an exactly equal motion of the other in theopposite direction.

The invention will be described in greater detail in connection with theaccompanying drawings of which:

Figure 1 is an elevational view of a plating machine;

according to the invention wherein a pair of reciprocating tension barsand a single, centrally-located hydraulic;

cylinder are employed to lift the chassis; Fig. 1A is a plan view of thetension bar assembly of the machine of Fig. 1; I I

'Fig. 2A is an elevational view of one end portion of a relatively largeplating machine according to the invention including two pairs ofreciprocating tension bars and'a single pair of equalizer bars, and alsoincluding two.

hydraulic actuating cylinders;

Fig. 2B is an elevational view of the central portion the platingmachine partly shown in Fig. 2A;

Fig. 2C is an elevational view of the opposite end por- Fig. 3B is adiagrammatic plan view of theycentral portion of the tension barassembly; a

Fig. 3C is a diagrammatic plan view of the opposite end portion of thetension bar assembly; V

Fig. 4A is a plan view'of one end portion of the complete tension barand equalizer bar assembly of the machine shown in Figs. 2A, 2B, and 2C;

Fig. 4B is a plan view of the central portion of the complete tensionbar and equalizer bar assembly of the machine shown in Figs. 2A, 2B, and2C; 7

Fig. 4C is a plan view of the opposite end portion of the completetension bar and equalizer bar assembly of the machine shown in Figs. 2A,2B, and 2C;

Fig. 5A is a diagrammatic plan view of one end portion of the equalizerbar assembly of the machine shown in Figs. 2A, 2B, and 2C;

Fig. 5B is a plan view of the central portion of the. equalizer barassembly of the machine shown in Figs. 2A, 2B, and 2C;

Fig. 5C is a plan view of the opposite end portion of the equalizer barassembly of the machine shown in Figs. 2A, 2B, and 20;

Fig. 6 is a fragmentary cross-sectional view showing the connectionbetween one of the equalizer bars and a tension bar; t

Fig. 7 is a plan view of the assembly shown in Fig. 6;

Fig. 8 is a side elevational view of a rack support bracket located nearthe equalizer gear box at the center of the machine, the view beingtaken in the direction of the arrow 8 of Fig. 4B; 7

Fig. 9 is a plan view of the bracket shown in Fig. 8;

Fig. 10 is a side elevational view showing the connection between a rackand a tension bar, theyieWbeing taken in the direction of the arrow 10of Fig. 4B;

Fig. 11 is a plan view of the assembly shown in Fig. 10;

Fig. 12 is a side elevational view of one of the equalizer bar supportbrackets, the view representing the area in the circle 12 of Fig. 2B; a

Fig. 13 is a sectional view through the upper frame channels withportions broken away showing a support bracket similar to the bracketshown in Fig. 12, the view being taken along the line 13-13 of Fig. 40;

Fig. 14 is a sectional view of the equalizer bar-tension bar assemblyshowing one equalizer bar and the rack at! tached to the other equalizerbar, the section being taken along the line 1414 of Fig. 4B;

Fig. 15 is a plan view of the equalizer gear box, the view representingthe area within the circle 15 in Fig. 4B; 7

Fig. 16 is a side elevational view of the equalizer gear box shown inFig. 15;

Fig. 17 is an end view of' the equalizer gearbox, the" 1C6 Patented Nov.29,1960;

view'being' a section through the upper frame channels and taken alongthe line 17-17 in Fig. 15.

Fig. 18 is a schematic elevational view illustrating the generalarrangement of the chassis lift mechanism of the machine shown in Figs.2A, 2B, and 2C; and

Fig. 19 isa schematic plan view of the lift mechanism illustrated inFig. 18.

One embodiment of the instant invention as shown in Figs. 1 and 1Acomprises a plating machine having a central frame including verticalcolumns braced by lower longitudinal channels 11 and 12, diagonalbracing members 13 and upper longitudinal channels 14. An elongatedchassis 16 of welded tubular construction is slidably mounted on thecentral frame and is provided with roller equipped guide brackets (notshown) which engage thevertical columns 10 for smooth vertical movement.A guide bracket such as the one shown in detail in Patent No. 2,479,322may be used here. At the center of the machine a double column 18supports a vertical hydraulic cylinder 20. A piston rod 22 projects fromthelower end of the cylinder 20, the upper end of the cylinder 20 beingsecured to the upper channels 14. The lower end of the piston rod 22 isprovided with a crosshead 24 received in vertical guides 26 secured tothe column 18. Two pairs of chains 28 and 30 are secured to thecrosshead 24, one pair at each side thereof, and extended vertically tobe trained over the sprockets 31 mounted between the channels 14 nearthe top of the machine.

A pair of tension bars 32, which overlap at an intermediate portion ofthe machine, are slidably supported in brackets 33 attached to the upperchannels 14. Racks 34 are secured to the tension bars along theoverlapping portions thereof and mesh with pinion gears 36 which aremounted on fixed pivots between the two racks 34. Thus, the tension barsare geared together and movement of one tension bar in one directioncauses the other tension bar to move in the opposite direction. One ofthe chains 28 is secured to the left-hand tension bar 32a, and one ofthe chains 30 is secured to the right-hand tension bar 3212. The otherones 28aand 30a of the two pairsof chains 28 and 30 are brought downover individual sprockets 40 to be secured to the chassis 16. Thus, whenthe piston crosshead 24 moves downwardly the tension bars 32 are drawntoward each other as indicated by the arrows 19.

Short lift chains 38 are secured to the chassis at spaced intervalsalong the length thereof. These lift chains 38 are extended upwardlyover sprockets 40 attached to the frame and secured to the tension bars32. When. the tension bars are moved together toward each other, theypullon the lift chains to lift the chassis. Since all the chains 28, 30and 38 are relatively short their stretching is minimized and, sincethey are all of substantially equal lengths, they all stretch in serviceby about the same amount. The chassis may, therefore, be raised and lowcred evenly and uniformly along its length and without binding orflutter.

A second and preferred embodiment of theinvention comprises aplatingmachine having separate tension and equalizer bars linked together andactuated by a plurality of hydraulic cylinders. This machine isillustrated in Figs. 2A, 2B, and 20, which may be aligned end to end toshow the complete machine. The machine is a relatively long one of theso-called return type and may be several hundred feet long. It has acentral frame comprising two double, vertical columns 18, and eightsingle, vertical columns 10. spaced along and rigidly. braced by.opposed pairs of bottom longitudinal channels 11, middle longitudinalchannels 12 and upper longitudinal channels 14.. The lower and middlelongitudinal channels 11 and 12, respectively, are further braced bydiagonal bracing members, such as the members 13 shownin the drawing.The frame construction is generally similar to the frame ofthe machineshown in Fig. 1, except that it is longer and includes more than onedouble column 18 adapted to support a hydraulic actuating cylinder. Achassis 16', of tubular metal frame work and generally similar to thechassis 16 heretofore described in connection with the machineillustrated in Fig. 1, is mounted on the columns 10 and 18 for verticalmovement between the channels 12 and 14. An angle iron, work-supportingrail 17 is secured to the chassis 16', and workpieces slidably supportedby hangers (not shown) on the rail 17 may be advanced around the machineby means of any convenient pusher rod mechanism such as the pusher rods21.

The general principle of operation for raising and lowering the chassis16 is illustrated schematically in Figs. 18 and 19, and reference shouldbe made to these figures in conjunction with the following description.

When in its lowered position, the chassis 16' rests upon the frame ofthe machine and may be supported by the middle longitudinal channels 12.When it is raised, the chassis 16' is supported by a series of chains28b, 30b, 38, 112 and 118 which are trained over sprockets and connectedto various other parts of the machine, as described in detailhereinafter. The chassis-supporting chains 38 and 118 are connectedbetween the chassis anda series of four tension bars -1, 100-2, 100-3,and 100-4 which are slidably supported on rollers 102 secured betweenthe upper frame channels 14, as shown in Figs. 2, 3 and 13. Each of thetension bars 100 comprises a pair of parallel rods secured together atvarious points along their length by spacer members 103 and 104 (Figs. 6and 7). The chassis lift chains 38 are attached to the ends of therespective tension bars by means of spacers 104 welded between the rodsof the tension bars, as shown in Figs. 6 and 7. Other chassis liftchains 118 are connected at intermediate points along the length of thetension bars in a similar manner to the chains 38, as shown in Fig. 3.

The tension bars are longitudinally actuatable by means of chains 28a,28c, 30a and 30c attached to the ends of the tension bars remote fromthe chassis lift chains 38. These actuating chains 28a, 28c, 30a and 30care trained over sprockets 31 and are attached to the crossheads 24 ofthe actuating hydraulic cylinder assemblies 20. They connect thelet-hand pair of tension bars 100-1 and 100-2 to the left-hand cylindercrosshead 24, and the right-hand pair of tension bars 100-3 and 100-4 tothe right-hand cylinder crosshead 24.

Each of the hydraulic cylinders 20 is similar in construction andmounting details to the hydraulic cylinder 20 heretofore described inconnection with the machine shown in Fig. 1. Each of the hydrauliccylinders 20 is mounted between the two posts of a double verticalcolumn 18 of the machine and has an upper base plate 20a fixed to abracket (not shown) secured between the channels 14. Each cylinder20includes a piston (not shown) to which is connected a piston rod 22.The piston rods 22 project from the lower ends of the cylinders and areprovided with crossheads 24 and 24, which are received in verticalguides 26 secured to the columns 18. The actuating chains 28a, 280, 30aand 30c are attached to the ends of the crossheads, as shown in Figs. 2Aand 2C. Thus, when the hydraulic cylinders 20 are extended they draw theactuating chains 28a, 28c, 30a and 300 downwardly to draw together theseparate pairs of tension bars 100-1 and 100-2, and 100-3 and 100-4, thetension bar 100-1 being drawn toward the tension bar 100-2, and thetension bar 100-3 being drawn toward the tension bar 10.0-4.Additionally, supplemental chassis lift chains 28b and 30b are attachedto the crossheads 24 and 24' and trained over the triple faced sprockets31, and over the single sprockets 33 and attached at their far ends tothe chassis 16. Thus, when the hydraulic cylinders 20 are actuated, thecrossheads 24 and 24' not only draw together the tension bars but alsothrough the lift chains 28b and 30b directly lift the chassis 16'.

A counterweight 110 is provided in each of the single columns at leastpartially to balance the weight of the chassis 16' and to minimize thelifting force required of the hydraulic cylinders 20. The counterweights110 are connected to the chassis 16 by means of chassis lift chains 112which are trained over sprockets 114 and 116 so that the counterweights110 move down when the chassis 16 is raised. (The counterweights 110 arenot indicated in Figs. 18 and 19.)

The tension bars 100-1 to 100-4 are tied together and their movementsequalized with respect to each other by an equalizer assembly includinga pair of equalizer bars 32a and 32b. The equalizer bars are I-beammembers slidably supported upon rollers mounted in brackets 50 attachedto the top of the upper, longitudinal frame channels 14. Details of themounting brackets 50 and the roller supports for the equalizer bars 32aand 32b are shown in Figs 12 and 13. Each of the brackets 50 comprises apair of short side channels 52, and a weldedon top channel 54. A smallangle bracket 56 is welded or otherwise attached to the top channel 54.A shaft 58 is secured between the side channel 52 and the angle bracket56 to support a pair of parallel, tapered rim roller wheels 60. Theequalizer bars 32a and 32b are supported upon the roller wheels 60 andare braced against lateral movement by a pair of horizontal rollers 64that roll against the web portion 66 of the equalizer bars, 32. Thehorizontal rollers 64 are individually mourited upon forwardly extendingbracket plates 62 which are secured to the side channels 52 of thebrackets 50. Thus supported, the equalizer bars 32a and 32b are freelyslidable longitudinally of the machine and are rigidly supported againstlateral displacement.

Each of the equalizer bars 32a and 32b extends about half the length ofthe machine. They terminate at their overlapping ends in racks 70a and7017, respectively, which are geared together through a pinion assembly76 in much the same manner as the racks 34 heretofore described inconnection with the machine shown in Fig. 1. As shown in Figs. 8 and 9,the racks 70 are supported upon rollers 74 mounted upon brackets 72which are bolted or otherwise attached to the upper frame channels 14.The racks 70 face each other and extend through the pinion assembly 76shown in greater detail in Figs. and 17. The ends of the racks 70 remotefrom their respective equalizer bars extend beyond the gear box 76 andare attached to different ones of the tension bars 100-2 and 100-3 asdescribed in greater detail herein after.

Referring now to Figs. 15-17, the equalizer pinion assembly 76 comprisesa lower gear plate 78, an upper gear plate 80 and upper and lower sidespacers 82 all secured together by bolts 84. The box 76 rests uponmounting pads 87 and is secured to the upper frame channels 14 by studbolts 86. A bearing mount bar 88 is secured between the upper and lowerside spacers 82 on each side of the box. Three small horizontallydisposed rollers 90 are mounted upon each of the bearing mount bars 88and make contact with the outer surfaces of the racks 70a and 70]),respectively, to maintain the racks in mesh with the pinion gears 92.Four pinion gears 92, each supported by a shaft 94 and a bearing 96, andsecured between the lower gear plate 78 and the upper gear plate 80, aremounted between the opposed racks 70a and 70b. Thus, movement of oneequalizer bar a predetermined distance in one direction causes theopposite equalizer bar to move an exactly equal distance in the oppositedirection.

The tension bars 100-1 to 100-4 are rigidly attached to the equalizerbars 32a and 32b and the racks 70a and 70b, as shown generally in Figs.4A-4C and in detail in Figs. 6, 7, l0 and 11. The tension bars 100-1 and100-3, that move toward the right as shown in the drawings when thehydraulic cylinders are extended, are connected to the equalizer bar 32aand to the rack 70a,

respectively. The tension bars -2 and 100-4,-that move toward the leftas shown in the drawing when the hydraulic cylinders 20 are extended,are rigidly attached to the equalizer bar 32b and the rack 70b,respectively. At the right-hand end of the machine the tension bar.100-4 is welded to a spacer plate 102 which is bolted to' the bottomflange of the equalizer bar 32b. Near the center of the machine thetension bar 100-2 is connected to the rack 70b by means of anangle ironbracket 106 welded to the tension bar members and bolted to the rack.correspondingly, tension bars 100-1 and 100-3 are similarly attached tothe equalizer bar 32a and to the rack 70a, respectively. Illustrativestructural details of these connections are shown in Figs. 10 and 11.

Thus, the tension bars are linked to each other through the equalizerassembly so that the tension bars 100-1 and 100-3 are forced .to movetogether in one direction, and the tension bars 100-2 and 100-4 areforced to move together an equal distance in the opposite direction. Anydifference or tendency toward a difference in the movement of or theforce exerted by different ones of the hydraulic cylinders 20 isequalized and distributed throughout the chasis lift mechanism by thetension bar-equalizer bar combination. Moreover,.the lift chains arerelatively short and are all of substantially equal lengths so that theproblem of differential stretch'between the chains is minimized. Thedifferent lift points along the length o f-the chasis 16 are all liftedand lowered simul-f taneously and synchronously, thus preventing bindingor flutter of the chassis.

It will be seen that any number of hydraulic cylinders such as thecylinders 20, electric motors or other actuating means may be utilizedin connection with a lift mechanism according. to this embodiment of theinvention. Each hydraulic cylinder or actuating motor would be linked toone pair of tension bars which it draws tog'ether when energized. Eachone of the tension bars" would then be attached to one of the twoequalizer bars depending upon its direction of movement when lifting thechassis 16'.

The use of reciprocating tension bars in combination with separateequalizer means provides symmetry to the structure and permitsrelatively simple alignment of ,the sprockets and the lift chains.Furthermore, if unbalanced forces are encountered, force from onetension bar is transmitted directly through an equalizer bar to anothertension bar so that strains on the equalizer pinion gears are minimized.

' What is claimed is:

1. Lift apparatus for an electroplating machine of the type having aframe and a chassis slidably mounted upon the frame for vertical travelrelative thereto, said apparatus comprising a pair of horizontal tensionbars mounted on the frame for horizontal travel relative thereto, aplurality of rotatable members pivoted upon the frame at longitudinallyspaced points near the top thereof, a plurality of flexible memberstrained over said rotatable members and connected between spaced pointsalong each of said tension bars and spaced points along the chassis,actuating means to move said tension bars horizontally with respect tothe frame, and equalizing means comprising a pair of racks and a fixedpoint pinion gear meshed with both said racks, said racks being rigidlyafiixed to respective ones of said tension bars so that a predeterminedtravel of one of said tension bars in one direction produces an equaltravel of the other one of said tension bars in the opposite direction.

2. Lift apparatus for an electroplating machine of the type having aframe and a chassis slidably mounted upon said frame for vertical travelrelative thereto, said apparatus comprising a plurality of tension barsmounted upon the frame for horizontal travel relative thereto, aplurality of rotatable members pivoted upon the frame at longitudinallyspaced points near the top thereof, a plurality of flexible memberstrained over said rotatable members and connected between spaced pointsalong each of said tension bars and spaced points along the chassis,fluid, actuating means to move said tension bars horizontally withrespect to said frame, a first means on each, of said tension, bars andsecond means cooperating with pairs of said first means for equalizingthe travel in opposite directions of said tension bars.

3. Lift apparatus for an electroplating machine of the type having aframe and a chassis mounted upon said frame for smoothly guided verticaltravel relative thereto, said apparatus comprising a plurality oftension bars slidably mounted upon the frame for horizontal travelrelative thereto, a plurality of rotatable members pivoted upon theframe at longitudinally spaced points near the top thereof, a pluralityof flexible members trained over said rotatable members and connectedbetween spaced points along each of said tension bars and spaced pointsalong the chassis, actuating means to move said tension barshorizontally with respect to said frame, and equalizing means comprisinga pair of equalizer bars mounted upon said frame for horizontallongitudinal movement relative thereto, a pair of racks, and a fixedpivot pinion gear, each of said racks being rigidly connected to adifferent one of said equalizer bars, said racks engaging diametricallyopposed portions of said pinion gear, and said equalizer bars beingrigidly connected to selected ones of said tension bars.

4. An electroplating machine comprising a frame, a

chassis mounted upon said frame for smoothly guided limited verticaltravel relative thereto, a plurality of horizontal tension bars slidablymounted on said frame above the upper limit, of travel of said chassis,a plurality of sprockets pivoted on said-frame, a plurality of liftchains trained over said sprockets and connected between spaced' pointsalong said tension bars and spaced points along said chassis, one end ofeach of said chains being fixedly connected to one of said tension bars,the other end of each of said chains being fixedly connected to saidchassis, said machine further comprising hydraulic cylinder meansconnected to said tension bars to produce horizontal travel of saidtension bars when said hydraulic cylinder means are actuated, a pair ofequalizer bars, a pair of racks, and a pinion gear, each of saidequalizer bars being rigidly connected to dilferent ones of said tensionbars, each of said racks being rigidly connected to a different one ofsaid equalizer bars, said racks engaging diametrically opposed sides ofsaid pinion gear, said pinion gear being rotatably mounted at a fixedpoint upon said frame.

5. An electroplating machine comprising in combination a frame, achassis mounted on said frame for vertical movement relative to saidframe, track means on said chassis for supporting work pieces andpropelling means associated with said track means for moving work piecesalong said track means, a plurality of pivot means mounted on saidframe, a plurality of tension bars on said frame disposed parallel tothe longitudinal axis of said chassis, a plurality of flexible memberstrained over said pivot means and attached to each of said tension barsand to said chassis at spaced points on each, a pinrality of fluidactuable power means mounted on said frame attached to said tensionbars, and equalizing means comprising first means on each of saidtension bars and second means cooperating with pairs of said first meansfor equalizing the travel in opposite directions of said tension bars.

6. An electroplating machine comprising in combination a chassis mountedon said frame for vertical movement relative to said frame, track meanson said chassis for supporting work pieces and propelling meansassociated with said track means for moving work pieces along said trackmeans, a plurality of pivot means mounted on said frame, a plurality oftension bars on said frame disposed parallel to the longitudinal axis ofsaid chassis, a plurality of flexible members trained over said pivotmeans and attached to each of said tension bars and to said chassis atspaced points on each, a plurality of power means mounted on said frameattached to said tension bars, and equalizing means associated with saidtension bars causing one tension bar to move a predetermined distance inone direction when anothe -tension bar moves a predetermined distance inthe opposite direction, said equalizing means comprising at least onepair of equilizer bars, said equilizer bars being rigidly connected toselected ones of said tension bars, a pair of racks and a pinion gear,each of said racks being rigidly connected to a different one of saidequalizer bars, and said racks engaging diametrically opposed portionsof said pinion gear.

References Cited inthe file of this patent UNITED STATES PATENTS 481,411Moran Aug. 23, 1892 1,107,702 Prescott Aug. 18, 1914 1,598,273 FitchAug. 31, 1926 2,479,322 Davis Aug. 16, 1949 2,633,855 Ransohotf Apr. 7,1953 2,711,831 Olson June 28, 1955 he A

